RESEARCH Open Access

Mineralogical and petrographical studies ofagricultural soil, Assiut Governorate, EgyptE. A. Abou El-Anwar* , H. S. Mekky, S. A. Salman, A. A. Elnazer, W. Abdel Wahab and A. S. Asmoay

Abstract

Background: The lack of information about the Egyptian soil needs more attention, especially mineralogical,petrographical studies, and quality data. Thus, the aim of this study was to evaluate the physicochemicalparameters of north Assiut agricultural soil; pH, moisture%, CaCO3%, organic matter (OM%), and mineralogicalcontents of the studied soil.

Results: The studied soil is characterized by alkaline nature, low organic matter, and high CaCO3%. Mineralogically, thestudied agricultural soil samples consist mainly of quartz, plagioclase, and minor calcite (as non-clay minerals), as wellas montmorillonite, vermiculite, and illite in decreasing abundance order as clay minerals. The plagioclase consists oftwo minerals; calcined albite and anorthite.

Conclusion: The clay minerals in the studied soils may be derived from the old alluvial plain (Plio-Pleistocene sediments)by successive Nile floods and reworking. The recorded clay minerals in the studied soils are montmorillonite, vermiculite,and illite in decreasing order of abundance. They have the ability to retain the irrigation water and adsorb moreexchangeable cations in aqueous media which can feed the plants.

Keywords: Mineralogy, Agricultural soil, Petrography, Assiut, Organic matter, Egypt

IntroductionThe soil constituents are inorganic minerals and organicmatter of different size and composition. The particles ac-count for about 50% of the soil’s constituents. Pores maycontain air and/or water represented the remaining vol-ume (Jensen 2000). The particle size distribution (PSD) ofsoil is one of the most basic physical attributes due to itsgreat effect on the other soil properties related to waterfaction, productivity, and soil erosion (Gimtnez et al. 1997;Montero 2005). The rate and extent of many physical andchemical reactions, including the sorption and desorptionof elements, are controlled by soil texture. Montero (2005)determines the amount of surface on which the reactionscan take place. Therefore, PSD can control the level ofmetal concentrations in soil. Fine particles (< 60 μm) aremore reactive and have a higher surface area than coarsermaterial (WHO 1982; Lin et al. 1998).Mineralogical constituents (especially clay minerals),

pH, moisture%, CaCO3%, and organic matter (OM%) gov-ern the productivity of soil (Salman: Geochemical and

environmental studies on the territories west River, un-published; Deshmukh and Aher 2014). Asmoay (2017)pointed out the prevailing of montmorillonite and kaolin-ite in the studied soils of Sohag and El Minya. Clay min-erals are so important to evaluate the magnitude of soilfertility (Miller and Donahue 1992).The soil of Nile Valley resulted from fluvial processes,

which mainly covers 3.5% of the total Egyptian lands. Itis compact when dry and swell when wet, due to the na-ture of the clay minerals epically montmorillonite. Thus,the clay minerals can keep water molecules with manysoluble ions required for plants. There is lack in assess-ment of the Egyptian soil requirements.Thus, the aim of this study was to assess the petro-

graphical and mineralogical characteristics of the northAssiut District agricultural soil. Furthermore, the sourceof the soil is the way to improve their nature. Mineral-ogical and petrographical studies were carried out onthe collected soil samples.

* Correspondence: abouelanwar2004@yahoo.comGeological Sciences Department, National Research Centre (NRC), 33 ElBohouth St. (former El Tahrir St.), Dokki, POB 12622, Giza, Egypt

Bulletin of the NationalResearch Centre

© The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, andreproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link tothe Creative Commons license, and indicate if changes were made.

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 https://doi.org/10.1186/s42269-019-0068-z

Materials and methodsThe study areaAssiut Governorate is located between latitudes 26° 50′and 27° 40′ N and longitudes 30° 40′ and 31° 32′ E andthe cultivated land extends along the two banks of theRiver Nile (Fig. 1). It comprises part of the Nile Valleyand parts of the surrounding plateaus. Assiut Governor-ate contains many big industries, such as cement,chemical fertilizers, detergents, and food. The study areaincludes mainly the relatively wide stretch extending tothe west of the Nile River.Many authors studied geology (Fig. 2) and structural

geology of the area (Said 1962 and 1981; Omara 1972 andYoussef et al. 1977; Omer 1996; Osman 1980; Shaker: Geoe-lectrical and hydrogeological studies on the area northwestof Assiut between Bani Adi and Mir, Nile Valley, Egypt, un-published; Khalifa et al. 2004). The present area is distin-guished into the following three main geomorphic units:

– The young alluvial plain (Holocene silty clay): it isoccupied by the cultivated lands bordering the westernside of the Nile. It is dissected by irrigation canals anddrains running from south to north parallel to theRiver Nile. The Nile tends to occupy the eastern sideof its valley in Assiut area so that the cultivated landsto the west of the river are generally much wider thanthose lands to the east.

– The old alluvial plain (Quaternary sand and gravel): Itoccupies the slope area between the calcareous plateau

and the young alluvial plain west of the River Nile. It isrepresented by terraces with various elevations abovethe young alluvial plain. The surface of the concernedunits is occupied, besides the old terraces, by elongatedsand dunes. The old terraces cover a considerable areaand formed mainly of travertine conglomerate withgravel, sandstone, and clay. While the sand dunescover extreme eastern areas of the scarp of thecarbonate plateau. It takes mainly the northwest-southeast direction and threats the cultivated landsof the present alluvial plains.

– The calcareous plateau: the eastern slope of thewestern calcareous plateau in the area of studyrepresents the western fringes of the Nile Valley. Ithas an elevation higher than floodplain varies fromsouth to the north. It is built up of Eocene limestonecovered by drift sands, flints, and boulders ofcarbonate. Dark brown to black gravelly plains areoccupying areas in the surface.

Sampling and analysesSixteen soil samples (30 cm depth) were collected aroundthe industrial activities in the study area, which is repre-sented the young alluvial plain (Fig. 1). The global position-ing system was used for locating the sampling points. Themineral composition of the investigated soil is recognized byX-ray diffraction analysis and petrographical investigation.Mineralogically, selected six samples were investigated by theX-ray diffraction technique at the Egyptian Mineral

Fig. 1 Location map of the studied soil samples

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 Page 2 of 9

Resources Authority (Dokki, Egypt) using a PANalyticalX-Ray diffraction equipment model X′Pert PRO with Sec-ondary Monochromator, Cu-radiation (λ= 1.542Å) at 45 kV,35 mA, and scanning speed 0.02°/s were used. The morph-ology and the size of the synthesized samples were character-ized via scanning electron microscopy (SEM) coupled withenergy-dispersive spectroscopy EDS (SEM Model QuantaFEG 250) in the National Research Center laboratories. Thereference data for the interpretation of the X-ray diffractionpatterns were obtained from the X-ray powder data file index(Smith 1961) in addition to the ASTM, X-ray diffraction cardfile (Poppe et al. 2001).

ResultsValues of the physical parameters showed that soilpH, moisture, OM, sand, silt, and clay average con-tents were 7.63, 3.5%, 2.4%, 39.2%, 33.9%, and 26.6%;respectively (Table 1). The close difference between

the mean and the median of the studied parametersindicted the unique factor controlling these parame-ters distribution.X-ray diffractometry (Fig. 3) revealed that the studied

agricultural soil samples consist mainly of quartz(65.05%), clay minerals (16.99%), plagioclase (17.31%),and minor calcite (0.65%). The clay minerals are com-posed of montmorillonite (10.8%), vermiculite (4%), andillite (1%) in decreasing order of abundance (Fig. 4). Theplagioclase consists of two minerals; calcine albite(15.4%) and anorthite (0.7%). Also, the SEM examinationof the soils samples showing montmorillonite (Figs. 5and 6), which is confirmed with the XRD results. In po-larizing microscopic examination, other less abundantminerals, such as amphiboles (3.6%), magnetite andhematite (4.4%), pyroxene (2.5%), garnet (1.6%), epidote(0.8%), and apatite (0.5%) of total sample matrix, weredetected (Figs. 7, 8, 9, 10, 11, and 12).

Fig. 2 Lithologic map of the studied Assuit area (After Conoco, Geologic map of Egypt 1987)

Table 1 Descriptive statistics of the physicochemical characteristics of the studied soils

Moisture% pH Sand% Silt% Clay% OM% CaCO3%

Mean 3.5 7.63 39.2 33.9 26.6 2.4 9.0

Median 2.9 7.68 32.7 37.3 27.5 2.4 7.3

Standard deviation 2.7 0.31 25.9 19.5 7.1 0.7 8.8

Minimum 0.6 6.91 6.3 2.8 16.0 1.0 0.5

Maximum 9.3 8.12 82.5 61.8 35.0 3.5 34.0

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 Page 3 of 9

DiscussionPhysicochemical propertiesSand and silt constitute the skeleton of the soil body,whereas clays constitute the reactive fraction of thesoil (Hillel 2004). The comparison of the current

results with other parts of the Nile valley (Table 2)indicated a little variation in the studied physico-chemical properties of soil. This variation may resultfrom the location, agricultural practices, and indus-trial activities. According to Folk (1974) triangle

Fig. 3 X-ray diffraction results of Assiut soil samples

Fig. 4 Folk triangle diagram of soil classification

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 Page 4 of 9

(Fig. 4), the studied soil samples can be texturallyclassified into three groups; sandy mud (eightsamples) muddy sand (four samples), clayey sand (twosamples), sandy silt (one sample), and mud (onesample).PSD represents the most significant soil physical and

even some soil chemical properties (Centeri et al. 2015).It is the most vital characteristic affecting pore geometry,porosity, pore size distribution, solid surface area, hydro-physical, and thermo-physical characteristics (Cartacuzencuet al. 2014; Mady and Shein 2017).PSD influence some factors such as moisture retention

and transmission properties; coarse-textured soils havelow moisture retention and high permeability. Whereasfine-textured soils have high moisture retention and lowpermeability. This may be indicated from the correlationbetween sand and moisture (Table 3). The soils with highclay content will have low permeability (Deshmukh andAher 2014). The clay fraction contains more alumina andhas a higher content of humus. Therefore, the propertiesof soils are affected by clay content rather than silt andsand particles. Thus, the authors thought that the mostimportant factors affecting the chemical properties of soilsin the study area referred to the higher proportion of theclay content. Because the fine particles have a largersurface area and hence be more reactive than coarserfractions (WHO 1982; Lin et al. 1998).The results of the present study show that the topsoil

layer of the study area exhibits a wide variation ofCaCO3 content, ranging from 0.5 to 34% (Table 1). Thestudied soils are considered calcareous soil because itcontains more than 5% CaCO3. These results were inagreement with the XRD which showed the presence ofcalcite (Fig. 3). Only samples (5 and 11) contain ananomalous value of CaCO3; these two samples areclosed to the electric power station and fertilizer factoryrespectively. This indicates that the factors influencing

the CaCO3 distribution are aridity, carbonate deposits,and human activity. Lime precipitates in the soil due tolimited leaching may be resulting from two processes;low rainfall/high evapotranspiration or restricting subsoillayers and associated saturated conditions (Netterber1978; Driessen and Deckers 2001). The distribution andamount of carbonates influence soil fertility. Theincrease of calcium carbonate in soil was led to a consid-erable decrease in the availability of most nutrients(Chein and Somponges 1987). Where carbonate min-erals cause immobilization of metals by providing anadsorbing and nucleating surface (Hassan 2015).The studied soil samples OM flocculated between 1

and 3.5% (Table 1). The results indicate that the studyarea soil contains low amount of OM. Loveland (2003)suggested that the major OM threshold in temperate re-gions is 3.4%, below which potentially serious decline insoil quality will occur. Accordingly, the quality of soil inthe study area is under stress because the studied sam-ples have less than 3.4% OM. The deficiency of OM

Fig. 5 SEM photomicrograph showing authigenic and detrital montmorillonite with ragged illite flakes, with face to face orientation(montmorillonite occurs as wavy sheets)

Fig. 6 SEM photomicrograph illustrating montmorillonite withrelatively well-crystallized illite. Note that montomorillonite occurs aswavy sheets

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 Page 5 of 9

could indicate that negligible amount of organic matteris added to soil in the form of crop residues and manure(Khan 1984). The aridity of the area and hot summertemperature could also lead to the degradation of OM(Tamhan et al. 1964). Also, it was found that tillageoperation disrupts soil structure and accentuates soil or-ganic matter oxidation by increasing aeration, whichstimulates microbial activity. Soils under cultivationusing irrigation and tillage generate optimal conditionsfor decomposition of OM (Quiroga et al. 1998; Ortega etal. 2002).

Mineralogical studyX-ray diffraction patterns (Fig. 3) revealed that the clayminerals content is low relative to the sand (quartz %),but they play an important role in supplying the

exchangeable cations, which required for plant nutrition.The investigated clay minerals display no specific patternof distribution in the studied area. The semi-quantitativeestimation showed obviously that there is general simi-larity in the common proportions of the clay minerals inthe investigated samples. Thus, it is strongly suggestedthe origin of soil from a common parent sedimentaryand metamorphic rocks. There is an abundance of clayminerals; montmorillonite and vermiculite are morethan illite mineral. The southern sector is characterizedby vermiculite and illite minerals. Therefore, the clayminerals in the studied agricultural soil samples are de-rived from continental source rocks throughout theRiver Nile, whereas in marine mud, the amount of illiteexceeds the amount of montmorillonite (Weaver 1989).

Fig. 7 Heavy fraction composed of opaque’s (black), zircon (zonedcolorless euhedral to subhedral grains), and staurolite (reddishbrown at the upper part of photo), heavy fraction, PPL. × 40

Fig. 8 Heavy fraction composed of opaque’s (isotropic), zircon(exhibits zoning and green, yellow, or upper part), heavy fraction,C.N. × 40

Fig. 9 Heavy fraction composed of opaque’s (black), zircon (zonedcolorless euhedral to subhedral grains), and staurolite (reddishbrown at the upper left corner), heavy fraction, PPL. × 100

Fig. 10 Heavy fraction composed of opaque’s (isotropic), zircon(exhibits zoning and green, yellow, or violet interference colors), andstaurolite (exhibits golden yellow interference colors at the upperleft corner), Heavy fraction, C.N. × 100

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 Page 6 of 9

SEM examination showed that the montmorilloniteoccurs as a medium to fine size particles and aggregates,and well-crystallized. The composition, morphology, andcrystallinity characteristics of the studied clay mineralsindicate that they are detrital and authigenic origin(Abou El-Anwar 2017, 2018; Abou El-Anwar et al. 2017,2018a, b). The abundance of montmorillonite refers todeposited under warm/humid climate (Abou El-Anwar2018; Abou El-Anwar and Samy 2013).Summing up the above-mentioned results, we can con-

clude that the encountered clay minerals assemblage inthe investigated soil samples is generally detrital and

authigenic in origin, mostly related and derived from Nilesediments. The drainage from the Ethiopian Highlandcomposed mainly of basic volcanic rocks which contrib-uted most of the mineral assemblages (cf. Abou El-Anwarand Samy 2013).

Petrographical studyThe occurrence of amphiboles, magnetite, hematite,pyroxene, garnet, epidote, and apatite indicate meta-morphic and intermediary or basic source rocks of soil(Omer 1996).The microscopic investigation of the heavy mineral frac-

tions (63 μm, grain size) of some sediments of the studiedarea confirmed that its mineralogical composition consti-tutes opaque minerals. The detected non-opaque mineralsare zircon, staurolite, and epidote in decreasing order ofabundance. Opaque’s represent the most abundant min-erals in the heavy fraction. They occur as blacksub-rounded to anhedral or irregular angular grains thatexhibit isotropism (Figs. 7, 8, 9, 10, 11, and 12).Zircon occurs as colorless euhedral to subhedral grains

that exhibit concentric growth zones (Figs. 7, 9, and 11).It shows green, yellow, or violet third-order interferencecolors (Figs. 8, 10, and 12). Staurolite occurs as darkbrown, reddish brown, yellowish brown, or brownishblack subhedral prismatic crystals (Figs. 7, 9, and 11). Itexhibits distinct pleochroism “colorless, yellow or red,golden yellow”. It shows golden-yellow interferencecolors (Figs. 8, 10, and 12). Epidote occurs as pale greenanhedral or irregular angular grains (Figs. 6, 7, 8, 9, 10,and 11). It exhibits green or yellow third-order of theinterference colors (Fig. 12).

Fig. 11 Heavy fraction composed of opaque’s (black), zircon (zonedcolorless euhedral to subhedral grains), staurolite (reddish brown atthe lower part), and epidote (pale green angular grains at the upperleft corner), heavy fraction, PPL. × 100

Fig. 12 Heavy fraction composed of opaque’s (isotropic), zircon(exhibits zoning and green, yellow, or violet interference colors),staurolite (exhibits golden yellow interference colors at the lowerpart), and epidote (exhibits yellow interference colors at the upperleft corner), heavy fraction, C.N. × 100

Table 2 Comparison between the soil physicochemicalproperties in the study area and other parts of Egypt

pH Sand% Silt% Clay% OM% CaCO3%

Current study 7.63 39.2 33.9 26.6 2.4 9.0

El Minya (Asmoay 2017) 7.94 33.86 39.49 24.55 2.81 16.58

El-Tebbin (Hassan 2015) 7.5 46.6 37.6 15.1 4.3 17.4

Sohag (Salman 2013) 8.1 20.6 51.2 28.1 2.3 8.7

Table 3 Correlation coefficient between the physicochemicalproperties of the studied soils

Moisture% pH Sand% Silt% Clay% OM% CaCO3%

Moisture% 1.00

pH − 0.14 1.00

Sand% − 0.48 − 0.19 1.00

Silt% 0.51 0.22 − 0.98 1.00

Clay% 0.36 0.09 −0.88 0.78 1.00

OM% 0.07 − 0.45 0.01 − 0.04 0.04 1.00

CaCO3% 0.40 0.16 − 0.02 0.09 − 0.19 0.00 1.00

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 Page 7 of 9

ConclusionThe studied agricultural soil samples minerals arequartz, clay minerals, plagioclase, pyroxene, amphiboles,biotite, garnet, and epidote and magnetic minerals. Thecultivated lands in the Nile valley are predominated bysandy silt soil type. With increasing of clay fraction, thesoil becomes compact, dark, high saline, alkaline, andseverely swells and shrinks. With increase sand fraction,it becomes loose, yellow, or gray and highly porous andpermeable. The main sources of nutrient (e.g., Ca, Mg,K, Fe, Mn, Cu, Zn, Ni) are plagioclase, mica, and maficminerals, which by weathering provide the soil with asignificant amount of these elements in a form availablefor plant nutrition.To improve the physical properties of sandy clay soil,

a significant amount of coarse-grained sand must beadded. In contrast, to decrease the porosity and perme-ability of the sandy soil, a considerable amount of siltand clay needs to added, which occurs within the Nileterraces from the old alluvial plain.

AcknowledgementsThe authors would like to thank The Geological Sciences Dept., National ResearchCentre for facilitates during this work.

FundingNRC internal project ID: 11080101.

Availability of data and materialsNot applicable.

Authors’ contributionsAll authors contributed equally in all article steps. All authors read and approvedthe final manuscript.

Ethics approval and consent to participateAccepted.

Consent for publicationAccepted.

Competing interestsThe authors declare that they have no competing interests.

Publisher’s NoteSpringer Nature remains neutral with regard to jurisdictional claims in publishedmaps and institutional affiliations.

Received: 8 November 2018 Accepted: 6 February 2019

ReferencesAbou El-Anwar EA (2017) Mineralogical, petrographical, geochemical, diageneses

and provenance of the cretaceous black shales, Duwi formation at Quseir-Safaga, Red Sea, Egypt. Egypt J Geol 26:915–926

Abou El-Anwar EA (2018) Lithologic characterization of the phosphorite bearingDuwi Formation (Campanian), South Esna, West Nile Valley, Egypt. CarbonateEvaporite. https://doi.org/10.1007/s13146-018-0442-1

Abou El-Anwar EA, Mekky HS, Abd El Rahim SH, Aita SK (2017) Mineralogical,geochemical characteristics and origin of Late Cretaceous phosphorite inDuwi formation (Geble Duwi Mine), Red Sea region, Egypt. Egypt JPetrol 26:157–169

Abou El-Anwar EA, Mekky HS, Abdel Wahab W (2018b) Geochemistry, mineralogyand depositional environment of black shales of the Duwi Formation,

Qusseir area, Red Sea coast, Egypt. Carbonate Evaporite. https://doi.org/10.1007/s13146-017-0417-7

Abou El-Anwar EA, Samy Y (2013) Clay mineralogy and geochemicalcharacterization of some Quaternary sediments on Giza-Fayium District, theNile Valley, Egypt: relationships to weathering and provenance. J Appl SciRes 9(8):4765–4780

Abou El-Anwar EA, Samy YM, Salman SA (2018a) Heavy metals hazard in Rosettabranch sediments, Egypt. J Mater Environ Sci 9(7):2142–2152

Asmoay ASA (2017) Hydrogeochemical studies on the water resources andsoil characteristics in the western bank of the River Nile between AbuQurqas and Dayr Mawas, El Minya Governorate, Egypt. PhD Thesis, Al-Azhar Univ, p 255

Cartacuzencu S, Lazar I, Nedeff V, Lazar G (2014) Technical solution to reduce soilerosion produced by Tazlau river in Tarata perimeter, Romania. Environ EngManag J 13:1971–1978

Centeri C, Jakab G, Szabo S, Farsang A, Barta K, Szalai Z, Biro Z (2015) Comparisonof particle-size analyzing laboratory methods. Environ Eng Manag J 14(5):1125–1135

Chein JH, Somponges D (1987) Evaluation of shortterm efficiency ofdiammonium phosphate versus urea plus single superphosphate on acalcareous soil. Agron J 79:896–900

Conoco, Geologic map of Egypt (1987) Egyptian general authority for petroleum.In: Scale (1:500,000), NG 36 NW Asyut

Deshmukh KK, Aher SP (2014) Particle size analysis of soils and its interpolationusing GIS technique from Sangamner area, Maharashtra, India. Intern. Res JEnviron Sci 3(10):32–37

Driessen PM, Deckers JL (2001) Lecture notes on the major soils of the world.World soil resources report 94. FAO, Rome

Folk L (1974) Petrology of sedimentary rocks. Hemplill, Austin, Texas, p 182Gimtnez D, Perfect E, Rawls WJ, Pachepsky Y (1997) Fractal models for predicting

soil hydraulic properties: a review. Eng Geol 48:161–183Hassan ISS (2015) Geochemical speciation and enrichment of toxic heavy metals

in Nile sediments and soils inEl-Tebbin area, Egypt. PhD Thesis, Fac Sci, AinShams Univ, Egypt, p 170

Hillel D (2004) Introduction to environmental soil physics. Elsevier/Acad. Press,San Diego, CA, p 494

Jensen JR (2000) Remote sensing of the environment: an earth resourceperspective. Prentice Hall, New Jersey

Khalifa MA, Abu El Gar MS, Helal S, Hussein AW (2004) Depositional history of theLower Eocene drowned carbonate platform (Drunka Formation), west of Assiutand El Minia stretch, Western Desert, Egypt. The 7Th International Conferenceon the Geology of the Arab World, Cairo Univ., pp 233–254

Khan GS (1984) Characterization of soils in the floodplains of Bannu Basin.Pakistan J Agric Res 5(1):51–58

Lin ZX, Harsbo K, Algren M, Qvarfort U (1998) The source and fate of Pb in thecontaminated soils at the urban area of flaun in Central Sweden. Sci TotalEnviron 209:47–58

Loveland P (2003) Webb J. Is there a critical level of organic matter in theagricultural soils of temperate regions: a review. Soil Till Res 70:1–18

Mady AY, Shein E (2017) Comparison between particle size distribution as apredictor of pedotransfer functions using laser diffraction and sedimentationmethods. Intern J Soil Sci 12(2):65–71

Miller RW, Donahue RL (1992) Soils: an introduction to soils and plant growth.Prentice-Hall, Inc., Englewood Cliffs, N.J.

Montero E (2005) Renyi dimensions analysis of soil particle-size distributions. EcolModel 182:305–315

Netterber F (1978) Dating and correlation of calcretes and other pedocretes.Trans Geol Soc S Afr 81:379–391

Omara S (1972) Limestone dykes in the Nile Valley around Assiut, Upper Egypt.N J b Geol Paleont Stuttgart:475–483

Omer AA (1996) Geological, mineralogical and geochemical studies on theNeogene and Quaternary Nile basin deposits, Qena-Assiut stretch, Egypt.PhD thesis, Geol Dept Fac Sci Sohag, South Valley Univ, p 320

Ortega RA, Peterson GA, Westfall DG (2002) Residue accumulation and changesin soil organic matter as affected by cropping intensity in no-till drylandagroecosystems. Agron J 94:944–954

Osman HZ (1980) Geological studies on the area to the northwest of Assiut M.Sc.thesis, Fac. Sci., Assiut Univ., Assiut, Egypt, p 276

Poppe LJ, Paskevich VF, Hathaway JC, Blackwood DS (2001) A laboratory manual forX-ray powder diffraction: U.S. Geological Survey Open-File Report 01-041;Woods Hole, MA. https://doi.org/10.3133/ofr0141.

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 Page 8 of 9

Quiroga AR, Buschiazzo DE, Peinemann N (1998) Management discriminantproperties in semiarid soils. Soil Sci 163(7):591–597

Said R (1962) The geology of Egypt. Elsevier Pub. Comp, Amesterdam, NewYork, p 377

Said R (1981) The geological evolution of the River Nile. Springer Verlag, NewYork, Heidelbeirg, Berlin, p 151

Smith JV (1961) Index to the X-ray powder file. Am Soc for testing materials,Philadelphia, p 3

Tamhan RJ, Motiramani DP, Bali TP, Donahue R (1964) Soil, their chemistry andfertility in tropical Asia. Prentice Hall of India, New Delhi

Weaver CE (1989) Clays, Muds and Shales. Elsevier, AmsterdamWHO (1982) Micropollutants in river sediments. Euro reports and studies 61,

CopenhagenYoussef MM, Riad S, Mansour HH (1977) Surface and structural study of the area

around Assiut, Egypt. Bull Fac Sci 6 Assiut Univ

Abou El-Anwar et al. Bulletin of the National Research Centre (2019) 43:30 Page 9 of 9